HDR/EXR Fireflies with Reflective Materials

[lunarstudio]

Hi. With the latest beta (and possibly previous versions), I'm encountering massive amounts of fireflies when using materials that have reflective properties in combination with HDRs/exrs being used in a separate daylight light (set to texture.) The main light is a separate daylight/sun.
I've tried adjusting kernel settings as well as hotpixel removal but it's quite brutal on some of my scenes and I don't know if this is a bug or simply the way HDRIs can interact with reflective mats (specular, glossy, and universal.)
Please advise. Thank you.

[SergKlyosov]

Hi lunarstudio,

Try to set GI clamp to a lower value

[paride4331]

Hi lunarstudio,
and have you forgotten to check importance sampling in OctaneDaylight?
Regards
Paride

[lunarstudio]

I tried it both on and off. I also tried with an EXR version of the same file and other HDRs. The fireflies make scenes almost unusable.
Removing reflections on mats are the only way to make these fireflies go away or to avoid HDRs entirely.

[paride4331]

Hi lunarstudio ,
my advise is never set specular = 1, roughness = 0
are you using adaptive samplig and denoiser?
Regards
Paride
if you

[lunarstudio]

Okay. Although some of the spec and rough settings actually have texture maps in them and I don't know what to do in this situation.
And yes, I have denoiser and adaptive sampling checked.

[lunarstudio]

Thanks Paride. Bringing the GI Clamp down to 10 REALLY helped.
I wasn't expecting to have to do that. Why is this value set so high by default?

[paride4331]

Thanks Paride. Bringing the GI Clamp down to 10 REALLY helped.
I wasn't expecting to have to do that. Why is this value set so high by default?

Hi lunarstudio,
As senorpablo said, you could try setting grey image texture to gamma 1
Regards
Paride

[lunarstudio]

Where is "grey image texture"?

[Elvissuperstar007]

HDR gamma 1.0 always change
CG clump 5-10
Ai light turn on
Filter size 1.0 detail
adaptive samplig turn on 2х2
ai denoiser turn on